role_type is in boost/beast/core/role.hpp (API Change):

This enumeration is now part of the library core and
not specific to websocket.

test/doc/websocket.cpp

@@ -0,0 +1,97 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#include "snippets.hpp"
+
+#include <boost/beast/_experimental/unit_test/suite.hpp>
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable: 4459) // declaration hides global declaration
+#endif
+
+//[code_websocket_1a
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/beast/ssl.hpp>
+#include <boost/beast/websocket.hpp>
+//]
+
+namespace {
+
+//[code_websocket_1b
+namespace net = boost::asio;
+using namespace boost::beast;
+using namespace boost::beast::websocket;
+
+net::io_context ioc;
+net::ssl::context ctx(net::ssl::context::sslv23);
+
+//]
+
+void
+websocket_snippets()
+{
+    {
+    //[code_websocket_1f
+
+        // This newly constructed WebSocket stream will use the specified
+        // I/O context and have support for the permessage-deflate extension.
+
+        stream<tcp_stream> ws(ioc);
+
+    //]
+    }
+
+    {
+    //[code_websocket_2f
+
+        // The `tcp_stream` will be constructed with a new strand which
+        // uses the specified I/O context.
+
+        stream<tcp_stream> ws(make_strand(ioc));
+
+    //]
+    }
+
+    {
+    //[code_websocket_3f
+
+        // The WebSocket stream will use SSL and a new strand
+        stream<ssl_stream<tcp_stream>> wss(make_strand(ioc), ctx);
+
+        //
+    //]
+    }
+}
+
+} // (anon)
+
+namespace boost {
+namespace beast {
+
+struct websocket_snippets_test
+    : public beast::unit_test::suite
+{
+    void
+    run() override
+    {
+        BEAST_EXPECT(&websocket_snippets);
+        pass();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(beast,doc,websocket_snippets);
+
+} // beast
+} // boost
+
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif